Urinary Blockage in Cats


Why Should I Bring my Cat to Willows for a Urethral Obstruction?

Willows is one of Europe’s leading small animal referral centres. Our state-of-the-art hospital is led by internationally renowned Specialists, committed to providing the highest standards of veterinary care. The Specialist-led Emergency and Critical Care (ECC) service provides advanced diagnostics and treatment for the most critical patients. Based within our advanced Intensive Care Unit the ECC service is fully supported by Willows’ experienced multi-disciplinary team.

Our Specialist ECC team have extensive experience in treating cats with urethral obstruction and have access to state-of-the-art equipment for diagnosis, stabilisation and treatment of patients ensuring the best possible treatment from start to finish. Willows provides round the clock care with Vets and highly trained Nurses on site 24 hours a day, every day of the year ensuring continued monitoring of critical cases with the ability respond quickly to any changes that may occur throughout the course of treatment.


What is a Urinary Blockage or Urethral Obstruction?

Producing urine is a form of eliminating toxins from the body. It is produced by the kidneys, after filtrating the blood, and stored in the urinary bladder. When the bladder is full the body will tells the brain to go the toilet. The urine then leaves the bladder through a tube (the urethra), which connects the bladder to the penis or the vagina. Every time there is an obstruction of the outflow of the urine, this is considered as an emergency because the bladder fills with urine but has nowhere to go and it can burst if it not treated.

Urethral obstruction is a problem that occurs almost exclusively in male cats, as the urethra of a male cat is much longer and narrower than that of a female, making it more susceptible to blockages. Urethral blockage is not a common condition, however when it occurs it is painful, the cat will be unable to urinate despite repeated efforts, leading to a potentially life-threatening emergency as it can cause acute kidney failure within two to three days if not managed appropriately.

Urethral obstruction can quickly become a life threatening situation. If you are unsure that your cat is urinating or if he/she shows signs of difficulty peeing or is lethargic, you should seek veterinary advice as soon as possible.

What are the Most Common Causes of Urethral Obstruction?

Several underlying conditions can cause obstruction of the urethra including:

  • A ‘plug’ in the urethra; this is often an accumulation of proteins, cells, crystals and debris in the bladder that accumulates and lodges in the urethra
  • A small stone (urolith) or an accumulation of very small stones; these form in the bladder but may become lodged in the urethra
  • Swelling and spasm of the urethra during inflammation of the bladder and urethra; The inflammation may cause swelling of the wall of the urethra contributing to a blockage, and in a number of cases the inflammation and irritation causes the muscle around the urethra (the urethral sphincter muscle) to go into spasm – this too can cause obstruction if the cat is not able to relax the muscle
  • Less likely cancer, granuloma and stricture

What are the Signs of Urethral Obstruction?

The typical clinical signs associated with a urethral obstruction in cats include; frequent visits in and out of the litter tray, becoming unsettled mewling and licking their penis. When the obstruction is partial, a few drops of urine will be present and will often be mixed with blood. If the obstruction is not treated straight away, the cat will became increasingly lethargic, uninterested in food, vomit and demonstrate discomfort when the abdomen is touched.


What Can I Expect if my Pet is Treated for a Urethral Obstruction?

Unfortunately, if a cat is predisposed to urethral obstruction, this increases the likelihood that it may recur. However, with good home management it is possible to reduce the frequency of the episodes. Home treatment aims to reduce the stress for the cat and increase the water consumption.

Home management tips

  • Increase the number of litter trays (No of litter trays = No of cats + 1)
  • Better hygiene of the litter box, to include frequent cleaning
  • Change the type of litter used
  • Environmental enrichment to stimulate hunter and hiding behaviour
  • Use of pheromones
  • Switch from dry food to wet food
  • Stimulate drinking by changing the water more frequently or using water fountains

Post-operative care

Following discharge it is important to reduce any potential stress for cats at home. It is important to continue the medication as prescribed by the Vet and monitor the frequency of urination.

Long term management

Preventing any further episodes of obstruction is the main long-term goal. Long term management aims to manage the underlying cause of the urethral obstruction. Cases associated with uroliths (stones in the urethra and bladder) can be managed with special diets to reduce the risk of their recurrence. Most cats with urethral spasm or urethral plugs are thought to have underlying feline idiopathic cystitis but where there are urethral plugs, diets to minimise crystals in the urine may also be helpful.

If repeated episodes of obstruction occur despite appropriate management, in some cases a surgical operation can be performed (called perineal urethrostomy) to help open and widen the narrow end of the urethra. This should not be regarded as a first line therapy however, as it does not deal with the underlying cause, and the surgery can sometimes be associated with complications such as the risk of stricture formation and an increased risk of bacterial urinary tract infections.


How is a Urethral Obstruction Diagnosed?

The diagnosis of urinary obstruction is made through a clinical examination. Examining the cat’s abdomen by touch the Vet will be able to feel if the urinary bladder is swollen, tense, painful and unable to be emptied. The clinical examination generally includes analysis of blood and urine samples and abdominal imaging (X-rays and/or ultrasound) to determine the cause of the blockage.

What Treatments are Available?

If a cat’s urethra is blocked, the obstruction needs to be removed quickly, it is however often necessary to perform a series of tests first to identify any complications. In particular, cats with a blocked urethra may develop acute kidney failure and very high blood potassium concentrations; these are life-threatening complications that should be checked when possible.

Under heavy sedation or anesthesia the urethra passing through the pelvis and penis of the cat will be carefully felt to locate the region of the obstruction. Often a catheter needs to be passed into the urethra (via the penis) so that fluids can be infused to help flush out the obstruction (or sometimes to push it back into the bladder). These procedures have to be carried out very carefully to avoid damaging the delicate lining of the urethra. The catheter will often stay in place for one to two days allowing the urine to return to a normal colour and for the kidney values to return to normal in the event that they were raised.

Following the procedure the cat will be given pain killers and a muscle relaxant. Once the urinary catheter has been removed and the cat is able to urinate independently he will be able to return home.

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Emergency and Critical Care

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To assist owners in understanding more about Emergency and Critical Care, we have put together a range of information sheets to talk you through some of the more common critical disorders cared for by our Specialists.